Exploratory Data Analysis

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Exploratory Data Analysis

• Histograms and Stemplots

2
Construct a Stemplot

• The Laboratory of Ornithology holds an annual
  Christmas Bird Count in which birdwatchers at
  various locations around the country see how many
  different species of birds they can spot. Here
  are some of the counts reported from sites in
  Texas during the 1999 event.

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The Data
4
Construct a Histogram

• A study examining the health risks of smoking
  measured the cholesterol levels of people who had
  smoked for at least 25 years and people of
  similar ages who had smoked for no more than 5
  years and then stopped. Create histograms for
  both groups and compare the distributions of
  their cholesterol levels.

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The Data for Smokers
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The Data for Ex-Smokers
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Critical Statistical Analysis 1B

• Find a dataset of at least 25 quantitative data
  observations.
• Construct a dotplot, stemplot, histogram and
  boxplot (standard or modified). If done by hand,
  use graph paper and a ruler.
• Calculate the mean, standard deviation, and
  five- number summary.
• Write a narrative as follows

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Paragraph One

• Introduce the data.
• What is it?
• Where did you get it?
• Look at one quantitative variable only. If your
  data is coming from a table that includes more
  than one variable, be clear about which column
  you are using.
• If you are not using the entire dataset, explain
  why and explain how you chose the points you
  chose.

9
New Paragraph(s)

• Comment on each graph. If you can integrate the
  graph with your text, great. If not, label your
  graphs with figure numbers and refer to the
  figures when you are writing about them.
• Comments should address shape, center, spread,
  outliers.
• Comments should also include a evaluation of the
  usefulness of that particular graph as a
  representation of the particular data you are
  analyzing

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New Paragraph(s)

• Explain which measures of center and spread would
  be appropriate to use.
• Explain why you chose that measure of center and
  spread.

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Due Date 10/10/07